fix: add module field to package.json for Parcel (#894)

Parcel's dependency resolution needs some fields in `package.json`. See below:

> `module` – An ES module version of the package.

-- https://parceljs.org/features/dependency-resolution/#package-entries

Author: ybiquitous

package.json

@@ -16,6 +16,7 @@
     "import": "./dist/index.js",
     "require": "./dist/index.cjs"
   },
+  "module": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "files": [
     "dist/",